Joe Friel's Blog is for the serious endurance athlete who wants to stay current on the science and art of training for sport. Here you will find Joe Friel's thoughts and ideas before they are published anywhere else. You may also visit www.TrainingBible.com for more detailed and free content. Joe's training plans are available at www.TrainingPeaks.com.

12/09/2013

Hard-Easy Training

“Polarized training” is a fancy new name for a basic old concept—train either at low or high intensity, but keep the moderate training time between these extremes relatively small. So what are low, moderate and high intensities? All of the recent polarized research studies define them, usually using heart rate as the standard, as follows…

Low. Called “zone 1.” Below the ventilatory threshold which is, essentially, the aerobic threshold (AeT). AeT is best determined in a lab test. It’s very roughly 30bpm below your anaerobic threshold (or lactate threshold, functional threshold, etc). This is a veryeasy workout that is commonly used for active recovery. (The reference to zones here is strictly for the purposes of these studies and not the same as the zones normally used by athletes.)

High. Called “zone 3.” Most of the studies use the respiratory compensation threshold. For our purposes, that is the equivalent of your anaerobic threshold (AnT). AnT is the intensity above which breathing becomes labored. This is a veryhard workout intended to improve performance.

Moderate. Called “zone 2.” As you might have guessed by now, this is the range between AeT and AnT.

The most recent study on this subject was reported in the May 2013 edition of the International Journal of Sports Physiology and Performance (1). A group of researchers from the European University of Madrid assigned 10k runners to either a polarized (emphasis on low intensity—zone 1) or a between-thresholds (emphasis on moderate intensity—zone 2) training protocol for 10 weeks. After the training period they repeated a 10km race on the same course used to establish a baseline before the 10-week period began. Both groups improved their performance times, but the polarized (low-high/zones 1 and 3) improved by 41 seconds more than the between thresholds (moderate-high/zones 2 and 3) group. The high intensity training time was about the same for both groups. The only thing that differed was how much time was spent in the low (z1) and moderate (z2) ranges.

The accompanying table summarizes this Spanish study along with two other older studies that followed a similar protocol (click to enlarge). Note that the groups which trained low-high performed better in the post-tests than the groups that trained moderate-high—in all three studies. (You can read the abstracts for each of the studies by clicking on the references below.)

Two other studies in the last few years took a look at how athletes distributed their intensities as they trained for real-world competitions. The first of these, from the same Spanish researchers again, followed 8, sub-elite, young (23 +/- 2 years old), male runners as they prepared over a 6-month period for the national cross country championships (4km and 10km) (4). Their average intensity distributions were:

Z1 = 71.3%

Z2 = 21.0%

Z3 = 7.6%

The researchers found that there was a close correlation between how much time was spent in zone 1 and performance time. In other words, the more zone 1 training, the faster they raced.

A second study out of Norway followed 11 junior Nordic skiers for 32 days of normal training and observed their intensities based on heart rate, ratings of perceived exertion (RPE) and lactate samples (5). The distributions for each of these testing methods was remarkably similar so I’ll just report heart rate distribution as the other studies have done:

Z1 = 75%

Z2 = 8%

Z3 = 17%

Following athletes as they train in the real world is often more revealing than lab studies. Note that the runners in the latter Spanish study did relatively little zone 3 training having 92% below AnT (combined zones 1 and 2). This is what I would expect to see from self-coached athletes. The Norwegian skiers had coaches, as we can tell from the lactate samples being taken. Note that they appear to have polarized the training intensities quite nicely.

One take-home message here is that there is nothing wrong with training below your aerobic threshold. In other words, really easy. Recovery is important. Too many athletes think the way to better performance is to raise the intensities on their recovery days. Not good. Easy, recovery workouts must be done in zone 1. And due to a lot of one’s training time being spent in zone 1, the quality of the high-intensity workouts (zone 3) improves. Doing a lot of zone 2 for recovery may well detract from your capacity to do the more valuable training above the anaerobic threshold.

Actually, I wish it was that simple. In the real world there are races done right smack-dab in zone 2, between AeT and AnT. For example, the race intensities of marathons, half marathons, Ironman and 70.3 triathlons all fit into this category. In fact, almost any race longer than an hour is a zone 2 event. One exception is road cycling in which the outcomes are determined largely by zone 3 (>AnT) efforts even though the race is mostly zone 2. So should you avoid training in this “toxic” zone? Perhaps not. It depends on what you are training for. As I continue to hammer home: You must prepare for a race by making your training increasingly like the race as you get closer in time to it.

The bottom line here is that the real issue is hard-easy training, not necessarily training predominantly in zones 1 and 3. It just so happens that each of the cited studies used subjects training for relatively short events. But that may not be you. Chances are it isn’t. So let’s say you are training for a 70.3 triathlon. Doing a workout with several 20-minute intervals in zone 2 (between AeT and AnT) with short recoveries could easily be a hard workout and yet not exceed AnT.

So “hard” is best defined relative to what you are training for and what the total stress load of a given workout may be—not necessarily what heart rate zone you were in. “Easy” is more easily defined, regardless of event duration, as being below your AeT.

Are you training in this way? The challenging part for most athletes is getting a lot of zone 1 time. But that’s the starting point. The quality and volume of your “hard” workouts will never be hard enough if you insist on trying to recover above your AeT.

Comments

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Hello,

Just wondering where on the Zone 1-3 continuum, the MAF (Maffetone) heartrate would be? I am 34 and generally train in the 145-150 range, but it is not what I would call "easy." I live at 5100' and this comports to a 5:45 mile on a track and a 10:00 pace on a 12% incline. 150HR is definitely not 30 beats below my Lactate Threshold. 150 is probably more like 20 beats under LT. The highest HR I have ever recorded was 186- about 5 years ago and long before I was cardiovascularly fit.

So based on this research, should I spend more time in the 140 BPM range- where exercise does feel much easier?

Excluding races and long hard days resulting in high levels of acute fatigue, I take the day off.

My recovery and performance have improved since I made the decision in the last two years to part with the "recovery ride."

The reality is, that time is the single greatest hurdle to most athlete's training. Some have too much, some have too little. Spending precious hours "noodling" around town is not an efficient use of time, and there is a cumulative mental price to pay as well.

Overtrainers need to get away from training for a day, and time strapped athlete's can't justify a "spin" at the expense of family, work, and other interests.

Why not take a day away from training and think about something else while your body recovers; and save that precious time for focused workouts? Surely that is the smart choice.

And why not apply this approach to amateurs AND professionals? I would be curious to see the results from training where athlete's spent more time in Zone 2 and 3, and very little dedicated time in Zone 1 (because they're relaxing on their sofas on those days).

So many athlete's get active recovery wrong--amateurs and pros. The simplest way to insure recovery and get it right is to NOT train, right?

I can ride a one hour hill climb with a HR at 170 or slightly above. When I'm doing a recovery ride, I'm usually at 120 or below. Riding at 135 BPM is well into and towards the upper range of my zone 2 power (coggan). Can you better describe zone 1 used in the study? Would it be easy zone 2 power?

I had always wondered about how effective intervals would be if we were not properly rested. I know myself if I have had a heavy 20+h week on the bike and 2-3 hours gym work that some z3-z4 intervals are really hard to get down. I often feel that the intervals could be wasted due to being a little over-fatigued and the quality was not there.

So like today my planner said "4h30 @ Z1+Z2 with 5-6x6m Z3 Tempo intervals" - I know for sure that if I had tried to do those intervals at the back end of the week being a little more fatigued and with some hours in the legs that the quality would not be there.

I hope I am misunderstanding your post, because if I am understanding it, it has rather radical implications for me. What I hope I am misunderstanding the translation between the five heart rate zones you normally use, e.g. in your Cyclist Training Bible, and the three zones discussed in this post; I am most worried about the upper boundary of Zone 1 of the three zones in the post. For me, if it is 30 bpm below lactate threshold, then Zone 1 of 3 in this post corresponds to Zone 1 of 5 in the Training Bible; According to this post, Zone 2 in the training bible now falls in the level of exercise to be avoided (which had previously only included Zone 3 of 5 from the Bible.) For me, Zone 1 (of 5) is painfully slow, certainly no fun whatsoever, does not feel like exercise, and is below what the establishment medical community claims is necessary to improve health. I know you don't know me and cannot comment on me specifically, so my general question for you is this:

For most athletes, would you estimate that the upper boundary of Zone 1 of 3 described in this post corresponds to the upper boundary of Zone 1 of 5 in your Training Bible? If not, could you estimate what it would generally correspond to?

For most amateurs finding time to train is one of the biggest limiters.

So rather than spend the vast majority of this in "active" recovery why not just do full rest and use the time saved for specific training in your target zone?

This would apply even to shorter events like the examples, even more so if, as you say your events are longer and therefore require more time at "hard" efforts.

It would help if the studies cited showed actual time spent in zone rather than percentages.

I find it hard to believe that someone who can only spend 8 hours per week training should be advised to spend 6 of these in "active" recovery and only average less than 20 minutes per day on hard efforts. Perhaps track sprinters may do this but for any event where time is measured in minutes rather than seconds?

On the other hand if you are doing an 24 hours per week = 1 hour per day in level 3 (assuming 1 day off) then yes you will need a lot of recovery but again do you really need 5 hours per day?

Joe, Interesting and timely article, especially since I've been reevaluating my training last season and decided that I didn't build much of a base and spent too much time on hard intervals.

These studies made no reference to the time spent training. It would seem to me that the percentages spent in Z1 and Z3 would vary depending on the total time training. A young, serious Cat 1 rider training 25 hrs a week should certainly need to spend a higher percentage of time in Z1 to recover from hard Z3 workouts. On the other hand, a 55+ master riding 8 or 9 hours a week would get their recovery from simply not riding. They could spend a much higher percentage of training time in Z3. Do you agree?

PS. Think my maths was a bit off in previous post, sorry for that. Still that doesn't alter point.

If someone is training for a 40km TT and only has 8 hours a week to spare if they spend 2 hours in level 3 and 6 in level 1 then their CTL will be very low and TSB very high. (If the two "hard" hours were done at FTP then I think CTL would be around 100*2/7=28ish?). Would this really be expected to yield significant benefits?

If the same person has 24 hours a week to spare then spending 6 hours a week doing "hard" efforts might well yield a benefit and their CTL would be in a more usual range, but still I did not think that spending 18 hours a week in level 1 would be significantly better than "only" 6-10 hours in terms of active recovery. Does it really?

Joe, in another article you stressed doing aerobic training at AnT -20bpm to fully stimulate the aerobic system, while in this article AnT -30bpm is suggested.

I think I've figured out my own answer, but would like confirmation. Should we focus on the AnT -20 more during Phase 1 basebuilding, when we're not doing any hard workouts, then ease back into the AnT -30 range to aide in recovery when we start getting into harder, more advanced and specialized training?

Or am I just splitting hairs? The pace difference between AnT -20 and AnT -30 is about 1 minute per mile for me, so it seems significant.

Joe,
The more I read about polarized training, the more important it looks. When calculating the amount of time spent in Z3 do you feel that it is basically HR alone that matters? Example: An hour workout with a 15 minute warm up and cool down and a 30 minute interval session of 30 repeats of 30 seconds @ V02max x 30 seconds rest. Not long into the intervals, HR fails to fall below threshold during the RI. HR totals for the workout are Z1 for 20 min, Z2 for 15 min and Z3 for 25 min. Only 15 min plus 5 min of the warm up were done working hard. Do you feel that time with HR in Z3, even if you are resting during that time, should be considered Z3 for purposes of hard/easy calculations?

Joe,
My thought is to Slim. If I do low intensity, like go on a group ride with seniors, yes it takes time but my heart works at a healthier rythmn than seated in front of that dangerous tv. My problem being health. I am nearly as strong as a young person. I need to become healthier. This requires those hours of easy workout. I run into problems when I get on the training bike, purposely made slow, and pushing. Instead of the zone one I end up in zone three. It does not lower my BP, the goal of my low intensity work out. Yes, Joe, read your book training over fifty or something like that. To complicated for me, but it has helped me to put in days off, like a week at a time.

geocof2249--I think that heart rate is actually very misleading for this purpose. For ex, to get to z3 you must go thru z2 yet the intensity is certainly above that when doing aerobic capacity intervals. Further complicating the matter is that heart rate rises very slowly and may not even make it to z3 when doing intervals shorter than 3 min. Power or pace are more accurate for this purpose, I believe.

Everyone is a little different, but based on observation I see far too many riders over the age of 50 spending too much time on the bike at recovery or endurance intensities.

Disclosure: I'm 38 and perfectly prepared to admit that I don't know what the hell I'm talking about.

That said, many of my friends and family all have the same complaint, "Riding is getting harder and I'm getting slower."

I'm not one to offer unsolicited advice, but I do offer tacit suggestions that my senior friends try mixing more structured intervals at high intensity. I'm not talking only about lactate threshold, I mean Vo2 and especially anaerobic efforts.

Again, I'm not there yet, but the Masters racers I know who work those high intensity zones are still kicking ass. At the very least, it's worth a 6-8 week trial. Oh, and take days off. Recovery rides are usually poorly executed. The physical penalty for taking the day off is minimal and the mental advantage is maximal!

Regarding road cycling, most base period workouts and muscular endurance workouts fall into the Z2 territory. So as I understand, polarized training would be more effective when training anaerobic endurance or power--maybe during the Build 2 or a week in the Peak period?